Abrasive disk



y 1933- A. J. DOERMANN 1,912,070

ABRAS IVE DISK Filed Sept. 14, 1931 Patented May 30, 1933 UNITED STATES PATENT OFFICE .ALBEBT J. DOERMANN, OF CHICAGO, ILLINOIS, .ASSIGNOR '10 TITAN ABRASIVES COM- IPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS ABRASIVE DISK Application filed September 14, 1981. Serial No. 562,807.

This invention relates to improvements in abrasive disks, grinding disks, and the like and, more especially, an abrasive disk mounted on a steel back. Among the features of my invention is the provision of a device of this kind using a very thin preferably pressed sheet metal back. I contemplate the formation of the back out of sheet metal of relatively thin gage, for example, 10, 14 or 16 gage sheet steel so that the material will be relatively inexpensive. The back can also be formed with slight labor, for example, by one or more pressing or punching operations. It is contemplated that the cost, therefore, of producing such a thin pressed sheet metal back will be so low that when the abrasive is used up, the back can be discarded. This will save the expense of boxing, handling and shipping backs to have them resurfaced with an abrasive.

Among the features of my invention is the provision of such' a steel back that is strong and durable. Improved means are provided for mounting fastening devices on the back and for protecting the heads thereof. Another feature of the invention is the provision of raised rings or corrugations in the back, thereby. protecting the heads of fastening devices and adding rigidity and stiffness tothe back member.

Another feature of my invention is the provision of an annular rim at the periphery of the sheet metal back to add rigidity and stiffness to the same and furnish additional protection and strength to the disk.

Other features and advantages of my invention will appear more fully as I proceed with my specification.

In those forms of devices embodying the features of my invention shown in the accompanying drawing- Figure 1 is a view in front elevation with parts broken away; Fig. 2 is a view taken as indicated by the line 2-2 of Fig. 1.

I shall first describe the form of device shown in Figs. 1 and 2. As here shown, 110

i may indicate the face plate, steel disk, or

other similar member of a disk grinder or other machine. It is to be understood that 110 indicates the rotatable member upon whichabrasive disks of the kind referred to are customarily mounted.

Numeral 111 indicates the metal back of the abrasive disk, here shown as made of relatively thin pressed sheet metal. This back is provided on its face with eight radiallv arranged ridges or raised portions 112. The back 111 is provided with a plurality of holes preferably adjacent and at the side of the ridges 112 for the accommodation of fastening devices. Such fastening devices are here shown as comprising threaded bolts 114 extending through said holes, said bolts having heads 114 adjacent the face of the back. As here shown, the heads 114 are lower than the height of the ridges 112. By means of this construction, said ridges serve as a protection to the heads. It will be noted that the heads are close to the ridges and do not project above them. With this construction, it will be seen that when the abrasive is nearly used up, the tops of the ridges 112 will be exposed as soon as the heads 114*. Any work then being applied to the disk will, therefore, contact with the ridg s 112 which are rounded on top before it w 11 be struck by the heads 114 of the fastening devices. This will protect the work from injury by such heads and will also indicate to a user that the abrasive disk needs to be renewed. The fastening devices 114 may be held in place on the back 111 by lock nuts 115. It is to be understood that the fastening devices 114 are adapted for the attachment of the abrasive disks to the face plate 110 in any suitable manner. example, the bolts 114 may extend through For holes in the face plate 110 and be engaged by nuts 116 at the back of said plate. Suitable depressions may be provided in the 'member 110 for accommodating the lock 1y narrower than the thickness of the abrasive.

Numeral 117 indicates a layer of abrasive on the back 111 fastened in any suitable manner as, for example, by the layer of cement 118.

The heads 114 may have flattened surfaces 114: contacting with one of the edges of one of the ridges 112 to prevent the head 114 from turning.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made Without departing from the spirit and scope of the invention as disclosed in the appended claim, in which it is my intention to claim all novelty inherent in my invention as broadly as permissible, in view of the prior 1 art.

What I regard as new, and desire to secure by Letters Patent, is:

An abrasive tool including a supporting member having a plurality of securing holes upon which a detachable, unitary homogeneous disk-like abrasive member is adapted to'be mounted, the said abrasive member comprising a disk of abradant, a backing therefor formed of a thin sheet metal disk having an upturned flange countersunk in the periphery of the abradant disk, the back of said sheet metal disk having spaced radial ridges struck up therein and extending into said abradant and out of contact with the supporting member, and provided adjacent 6 said ridges with a plurality of openings adapted to register with the holes in said supporting member, fastening devices extending into said openings and holes and having non-circular heads, said heads being substantially in the plane of but slightly below and engaging said ridges, whereby the heads are protected when said abradant disk is worn down to the level of said ridges and prevented from rotation by contact with said ridges, locking means for holding said devices in place, and a layer of adhesive in terposed between the abradant and the sheet metal disk.

In witness whereof, I have hereunto set my hand this 11th day of Se tember 1931.

ALBERT J. D ERMAivN. 

